At least 40 people have been killed in twin explosions near religious shrines frequented by Shiite pilgrims in the Syrian capital, Damascus, according to Syria's interior minister and media reports.

Syria state TV aired footage from the scene showing blood-soaked streets and several damaged buses in a car park, apparently where the blasts went off near the Bab al-Saghir cemetery. The cemetery is one of the capital's most ancient and is where several prominent religious figures are buried.

Interior Minister Mohammed al-Shaar visited the casualties in local hospitals.

He said 40 had been killed and 120 others injured in the attacks, which targeted civilians, including Arab visitors, who were frequenting the shrines in the area.

He did not elaborate, but Iraqi Shiites often visit shrines in Syria. Iranians and other Shiites from Asia are often also among the pilgrims to the area.

There were conflicting reports on what caused the explosions.

State news agency Sana said the blasts were caused by bombs placed near the cemetery and that at least 33 people were killed and more than 100 others wounded.

Lebanon's al-Manar TV quoted Syrian officials as saying twin suicide attacks had killed 40. Arab TV Al-Mayadeen said at least 40 were killed, and the area was sealed by security after the explosions.

The Britain-based Observatory for Human Rights, an opposition monitoring group with activists on the ground, said at least 46 people were killed in the explosions which targeted buses arriving near the cemetery. The Observatory said the death toll is likely to rise because dozens were injured.

A similar attack in the capital last year targeted one of the most revered Shiite shrines and was claimed by Islamic State militants.

Bab al-Saghir is one of the seven gates of the old city of Damascus and houses a cemetery where a number of early Islam religious figures, including family members of Prophet Muhammad and figures revered by Shiites, are buried.

Meanwhile, Syrian President Bashar Assad has told a Chinese TV station that his military's priority is to reach the Islamic State group's de-facto capital of Raqqa - towards which US-backed Kurdish-led forces are also advancing.

In the interview with Hong-Kong based Phoenix TV broadcast on Saturday, Mr Assad said another IS stronghold, Deir el-Zour, could be targeted in parallel.

He said "in theory" he shares the same priority with US President Donald Trump of fighting terrorism, but that they have had no formal contact yet.

He added that Russia, a major ally, hopes it can bring the US and Turkey into co-operating with Moscow and Damascus in the fight against terrorism in Syria. The Assad government views all armed opposition as terrorist groups.

Mr Assad said all foreign troops on Syrian soil without invitation or consultation with the Syrian government are considered "invaders".